javascript - Second php file can't find Session started in first file -

i can't php $_session variable work way want to. i've got 2 files. first 1 setting variable:

<?php     session_start();     header("access-control-allow-origin: *");     $_session['authenticated'] = "yes";     echo json_encode('authenticated successfully.'); ?> 

and second 1 trying retrieve it:

<?php     session_start();     header("access-control-allow-origin: *");     print '<pre>';     var_dump($_session['authenticated']);     print '</pre>'; ?> 

but second file prints null when should print "yes" , new error recorded in server's log:

[thu sep 22 12:52:47.763114 2016] [:error] [pid 26644] [client <ip_here>] php notice:  undefined index: authenticated in <second_file> on line 5, referer: <client_url_here> 

both files accessed ajax calls javascript.

the ajax code file 1 works following:

$.ajax({         url: corrdomain + '/auth.php', //path , name of file #1. it's correct , working.         type: 'post',         data: {             //this part excluded in above php code simplification. it's guaranteed work.             username: username,              password: password,             action: 'init'         },         datatype: 'json',         success: function(data){           //check if data contains right information, call function file #2.         },         error: function(){           //something went wrong         }     }); 

when code gets thumbs php, user authorized following code run file #2:

$.ajax({     url: path + '/getproducts.php', //also correct , working.     type: 'post',     datatype: 'json',     success: function(data){         products.push(data);         orderproductids();          //update col 1 + 2;         updateorders('reload');          //set interval of updating col 1.         setinterval(function(){             updateorders('update');         }, 10000);     },     error: function(){                   alert('something went wrong.');     } }); 

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update: added session_name(); first row in php files. session works if open each file in browser not if access them via ajax. problem still persists, maybe can me.

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update #2: in chrome's web inspector can see both files returning session cookie ids, have different values. see screenshots.

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update #3: i've researched , found php sessions isn't possible when using phonegap, though i'm requesting php file via jquery ajax. can confirm this?

make sure start session session_start(); on page makes ajax calls

edit

a not preferable maybe usefull method send session_id each ajax request use more token.

the first php-script:

session_start(); echo json_encode([     'message' => 'session started',     'session_id' => session_id() ]); exit(); 

store received id in javascript-variable:

var session_id;  $.ajax({     ...     success: function(data) {         session_id = data.session_id;     }     ... } 

after send session_id along each ajax-request:

var data = {session_id: session_id, ... };  $.ajax({     type: "post",     url: "server.php",     data: data,     success: function(data) {      } }); 

instead of session_id can generate random token instead send along each request.